How to average logarithmic retrievals?

Calculation of mean trace gas contributions from profiles obtained by retrievals of the logarithm of the abundance rather than retrievals of the abundance itself are prone to biases. By means of a system simulator, biases of linear versus logarithmic averaging were evaluated for both maximum likelihood and maximum a priori retrievals, for various signal to noise ratios and atmospheric variabilities. These biases can easily reach ten percent or more. As a rule of thumb we found for maximum likelihood retrievals that linear averaging better represents the true mean value in cases of large local natural variability and high signal to noise ratios, while for small local natural variability logarithmic averaging often is superior. In the case of maximum a posteriori retrievals, the mean is dominated by the a priori information used in the retrievals and the method of averaging is of minor concern. For larger natural variabilities, the appropriateness of the one or the other method of averaging depends on the particular case because the various biasing mechanisms partly compensate in an unpredictable manner. This complication arises mainly because of the fact that in logarithmic retrievals the weight of the prior information depends on abundance of the gas itself. No simple rule was found on which kind of averaging is superior, and instead of suggesting simple recipes we cannot do much more than to create awareness of the traps related with averaging of mixing ratios obtained from logarithmic retrievals.The authors like to thank the Toronto SPARC office and the International Space Science Institute (ISSI) in Berne for hosting team meetings where the issue of this paper became evident and for providing generous travel support. The authors would also like to thank the team members of the SPARC Data Initiative led by Michaela Hegglin and Susann Tegtmeier for triggering our interest in this interesting problem, and Charles Jackman for kindly providing WACCM model results. BF was supported by by the Spanish MICINN under project AYA2008-03498/ESP and project 200950I081 of CSIC.Peer Reviewe

DEPRESSION AND STRESS AS CORRELATES OF SUICIDE THOUGHT AMONG UNDERGRADUATES OF IMO STATE UNIVERSITY, OWERRI.

This study investigated Depression, self-esteem and stress as correlates of suicide thoughts among university students of Imo State University, Owerri. Using a descriptive survey design, the study adopted a purposive sampling technique to select 402 undergraduates (208 males and 194 females) from all the 12 faculties of Imo state University, Owerri. Beck Depression Inventory, Becks’ Suicide Ideation Inventory and the Rosenberg self-esteem scale were used as instruments for data collection. Data analysis was done using Pearson Product Moment Correlation (PPMC) at a .05 level of significance. The study revealed a significant correlation between the independent variables (Depression, self-esteem and stress) and the dependent variable (Suicide thought) in the following order, Depression R=(400) = 0.216, p<.05, Self-esteem R=(400) = 0.314, p<.05 and Stress R=(400) = 0.174, p<.05). Among the recommendation is the fact that Lots of awareness and knowledge about suicidal thoughts among undergraduates should be created to provide a guideline for possible prevention program or treatments for those students who are experiencing the ideas of suicidal. This study came to existence to raise awareness about suicidal ideations' risk factors and prevention so that university students in crisis may be recognized and helped

TRAUMA AND STRESSOR-RELATED DISORDERS AMONG INTERNALLY DISPLACED PERSONS IN THE FEDERAL CAPITAL TERRITORY, ABUJA

This paper assesses stress and trauma-related disorders among the Internally Displaced Persons in the Federal Capital Territory, Abuja, Nigeria. In its methodology, the study took a descriptive approach. A convenient sample of 300 participants were drawn from each of the four officially recognized camps in the FCT making a total sample of 900 participants for this study. Face-face interview was conducted using interviewer administered structured questionnaire. Two additional research assistants and two Hausa interpreters were recruited for this study. The response rate was 100 percent. Anxiety, adjustment and attachment disorders were most prevalent in this study. Traumatic stress disorders were higher in respondents aged 37-58, and the unemployed. The interview was face-face and psychological tools like PHQ-9, PHQ-GAD, PHQ-SADS were used. Findings showed that a large proportion of the respondents are less educated, 94% of respondents were unemployed as at the time of this study. (67%) and those separated from spouses and family as a result of Boko-harm attacks. Recommendation made was that getting timely help and support may prevent normal stress reactions from getting worse and developing into PTS

DEPRESSION AND STRESS AS CORRELATES OF SUICIDE THOUGHT AMONG UNDERGRADUATES OF IMO STATE UNIVERSITY, OWERRI.

This study investigated Depression, self-esteem and stress as correlates of suicide thoughts among university students of Imo State University, Owerri. Using a descriptive survey design, the study adopted a purposive sampling technique to select 402 undergraduates (208 males and 194 females) from all the 12 faculties of Imo state University, Owerri. Beck Depression Inventory, Becks’ Suicide Ideation Inventory and the Rosenberg self-esteem scale were used as instruments for data collection. Data analysis was done using Pearson Product Moment Correlation (PPMC) at a .05 level of significance. The study revealed a significant correlation between the independent variables (Depression, self-esteem and stress) and the dependent variable (Suicide thought) in the following order, Depression R=(400) = 0.216, p<.05, Self-esteem R=(400) = 0.314, p<.05 and Stress R=(400) = 0.174, p<.05). Among the recommendation is the fact that Lots of awareness and knowledge about suicidal thoughts among undergraduates should be created to provide a guideline for possible prevention program or treatments for those students who are experiencing the ideas of suicidal. This study came to existence to raise awareness about suicidal ideations' risk factors and prevention so that university students in crisis may be recognized and helped

The Use of the "Preclosure” Technique for Antegrade Aspiration Thrombectomy with Large Catheters in Acute Limb Ischemia

Purpose: This study was designed to assess retrospectively short- and mid-term outcomes of the use of a suture-mediated closure device to close the antegrade access in patients undergoing percutaneous aspiration thrombectomy with large catheters for acute leg ischemia. Methods: Between November 2005 and February 2010, a suture-mediated active closure system (ProGlide® 6F, Abbott) was placed before arterial sheath (mean 9F, range 6-12F) introduction in 101 patients (74 men, 73%, mean age 70.1±12.6years standard deviation). Data regarding mortality, complications, and factors contributing to vascular complications at the access site was collected for 6month after the intervention to detect device-related problems. As a coincidence, 77 patients had follow-up visits for a duplex ultrasound. Results: There were a total of 19 vascular complications (19%) at the puncture site, all of which were of hemorrhagic nature and none of which consisted of vessel occlusion. Two major outcome complications (2%) occurred. A retroperitoneal hematoma and a serious inguinal bleeding required additive treatment and did not result in permanent sequelae. Nine cases involved death of which eight were not attributable to the closure and one remained unclear. Successful closure was achieved in 95 patients (94%); additional manual compression was sufficient in the majority of the remaining patients. Numerous factors contributing to vascular complications were encountered. Conclusions: With acceptable short- and mid-term outcomes, the "preclose” technique can be a reliable option for the closure of a large antegrade femoral access even for patients at a high risk of vascular complications, such as those undergoing aspiration thrombectom

Nutritional composition of formulated complementary food produced from blends of malted and unmalted yellow maize (Zea mays), soybean (Glycine max), and tiger nut (Cyperus esculentus) flour

Protein-energy malnutrition (PEM) and micronutrient deficiencies among infants and children in developing countries have been a major concern of the World Health Organization. Formulation of complementary food from local sources of raw materials can be of great help in solving the problems of protein energy malnutrition. This study determined the nutritional composition of four formulated complementary foods from malted yellow maize, pre-gelatinized yellow maize, soybean, and tiger nut flour. The results showed an increase in protein content (17.6, 16.9, 20.4 & 19.7 %), crude fat (14.9, 12.9, 13.0 & 12.9 %) and energy (433.1, 419.4, 421.5 & 426.6 %) when compared with the control sample. The functional properties also competed favourably with the control sample, with the formulated samples having water absorption capacity (171.9, 169.0, 184.1 & 167.4 %), swelling power (27.9, 25.2, 29.8 and 28.1 %), and bulk density at the same level for all the formulated samples (0.5 g/ml). The formulated samples contained a higher amount of iron and magnesium, and the anti-nutritional factors fell below the hazard level. In conclusion, formulated complementary food made from locally sourced raw materials has enough nutritional composition to be able to combat PEM and micronutrient deficiencies among infants and children

A method for merging nadir-sounding climate records, with an application to the global-mean stratospheric temperature data sets from SSU and AMSU

A method is proposed for merging different nadir-sounding climate data records using measurements from high-resolution limb sounders to provide a transfer function between the different nadir measurements. The two nadir-sounding records need not be overlapping so long as the limb-sounding record bridges between them. The method is applied to global-mean stratospheric temperatures from the NOAA Climate Data Records based on the Stratospheric Sounding Unit (SSU) and the Advanced Microwave Sounding Unit-A (AMSU), extending the SSU record forward in time to yield a continuous data set from 1979 to present, and providing a simple framework for extending the SSU record into the future using AMSU. SSU and AMSU are bridged using temperature measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), which is of high enough vertical resolution to accurately represent the weighting functions of both SSU and AMSU. For this application, a purely statistical approach is not viable since the different nadir channels are not sufficiently linearly independent, statistically speaking. The near-global-mean linear temperature trends for extended SSU for 1980–2012 are −0.63 ± 0.13, −0.71 ± 0.15 and −0.80 ± 0.17 K decade−1 (95 % confidence) for channels 1, 2 and 3, respectively. The extended SSU temperature changes are in good agreement with those from the Microwave Limb Sounder (MLS) on the Aura satellite, with both exhibiting a cooling trend of ~ 0.6 ± 0.3 K decade−1 in the upper stratosphere from 2004 to 2012. The extended SSU record is found to be in agreement with high-top coupled atmosphere–ocean models over the 1980–2012 period, including the continued cooling over the first decade of the 21st century

Local impact of solar variation on NO2 in the lower mesosphere and upper stratosphere from 2007 to 2012

MIPAS/ENVISAT data of nighttime NO2 volume mixing ratios (VMR) from 2007 until 2012 between 40 km and 62 km altitude are compared with the geomagnetic Ap index and solar Lyman-α radiation. The local impact of variations in geomagnetic activity and solar radiation on the VMR of NO 2 in the lower mesosphere and upper stratosphere in the Northern Hemisphere is investigated by means of superposed epoch analysis. Observations in the Northern Hemisphere show a clear 27-day period of the NO2 VMR. This is positively correlated with the geomagnetic Ap index at 60-70° N geomagnetic latitude but also partially correlated with the solar Lyman-α radiation. However, the dependency of NO2 VMR on geomagnetic activity can be distinguished from the impact of solar radiation. This indicates a direct response of NOx (NO + NO2) to geomagnetic activity, probably due to precipitating particles. The response is detected in the range between 46 km and 52 km altitude. The NO2 VMR epoch maxima due to geomagnetic activity is altitude-dependent and can reach up to 0.4 ppb, leading to mean production rates of 0.029 ppb (Ap d)-1. Observations in the Southern Hemisphere do not have the same significance due to a worse sampling of geomagnetic storm occurances. Variabilities due to solar variation occur at the same altitudes at 60-70° S geomagnetic latitude but cannot be analyzed as in the Northern Hemisphere. This is the first study showing the direct impact of electron precipitation on NOx at those altitudes in the spring/summer/autumn hemisphere. © 2014 Author(s).F. Friederich and M. Sinnhuber gratefully acknowledge funding by the Helmholtz Association of German Research Centres (HGF), grant VH-NG-624Peer Reviewe

Local impact of solar variation on NO2 in the lower mesosphere and upper stratosphere from 2007 to 2012

MIPAS/ENVISAT data of nighttime NO2 volume mixing ratios (VMR) from 2007 until 2012 between 40 km and 62 km altitude are compared with the geomagnetic Ap index and solar Lyman-α radiation. The local impact of variations in geomagnetic activity and solar radiation on the VMR of NO 2 in the lower mesosphere and upper stratosphere in the Northern Hemisphere is investigated by means of superposed epoch analysis. Observations in the Northern Hemisphere show a clear 27-day period of the NO2 VMR. This is positively correlated with the geomagnetic Ap index at 60-70° N geomagnetic latitude but also partially correlated with the solar Lyman-α radiation. However, the dependency of NO2 VMR on geomagnetic activity can be distinguished from the impact of solar radiation. This indicates a direct response of NOx (NO + NO2) to geomagnetic activity, probably due to precipitating particles. The response is detected in the range between 46 km and 52 km altitude. The NO2 VMR epoch maxima due to geomagnetic activity is altitude-dependent and can reach up to 0.4 ppb, leading to mean production rates of 0.029 ppb (Ap d)-1. Observations in the Southern Hemisphere do not have the same significance due to a worse sampling of geomagnetic storm occurances. Variabilities due to solar variation occur at the same altitudes at 60-70° S geomagnetic latitude but cannot be analyzed as in the Northern Hemisphere. This is the first study showing the direct impact of electron precipitation on NOx at those altitudes in the spring/summer/autumn hemisphere. © 2014 Author(s).F. Friederich and M. Sinnhuber gratefully acknowledge funding by the Helmholtz Association of German Research Centres (HGF), grant VH-NG-624Peer Reviewe